In the fields of human interaction where a human and a machine make contact with each other, a position of an object disposed remotely and force acted on the object are desired to be controlled with good response corresponding to an operation of a man. For example, in such a field as a remote operation apparatus used in a working field in which a man can not physically enter or a remote medical care apparatus for patients living at remote locations, a master/slave control device is used in which the slave side device disposed at a remote place is actuated in response to an operation of the master side device by an operator. For a master/slave control device of this sort there is a demand for realization of a delicate work by controlling a position of an object and force acted on the object with good response.
There are known as the aforementioned master/slave apparatus a unilateral control system where although it can send an instruction from an operator via a master side apparatus to a slave side apparatus, it cannot feedback the work reaction force which the slave side receives from a work object or the like, to an operator, and a bilateral control system where it can send an instruction from the operator via the master to the slave side apparatus, and it can feed back work reaction force which the slave side receives from the work object or the like, to the operator.
Since the bilateral control system feedbacks the work reaction force which the slave receives from the work object or the like to the operator, it is possible to obtain a tactile sensation at a remote site in real time as in reality.
The control device of the bilateral control system constructed by a master/slave type robot feedbacks any force applied to a remote slave to a man through the master. It is also possible that a man can make the slave take the same movement as the master by operating the master. This imparts to an operator the sense that he directly touches a remote object.
Reference 1 proposes one example of such a master/slave control device.
The master/slave control device disclosed in the reference 1 is constituted in such a manner that in a master/slave device where a slave is operated in response to an operation of the master by an operator, when a slave makes contact with an object, force f1 applied to the master by an operation of an operator is estimated and controls the slave such that force f3 applied to the slave follows force f2 in response to the force f1 applied to the master, and the device can retain the control system in the less complicated configuration without additional cost, while keeping the merit of the bilateral control system intact.
FIGS. 14 and 15 illustrate those disclosed also in the reference 1 known as the bilateral control system.
The system illustrated in FIG. 14 is so configured that a deviation between the position of a master 201 and that of a slave 202 is estimated, on the basis of which a position control section 203 controls the position of the slave, and forces acted on the master 201 and the slave 202 are detected by a force detector to feedback a deviation between the forces to a master side, hereby controlling the force of the master side by a force control part 204.
The system illustrated in FIG. 15 is so configured that a deviation between a position of a master 201 and a position of a slave 202 is estimated, in response to which a position control section 203 controls a position of a slave side and a position control section 203′ controls a position of a master side, and further forces acted on the master 201 and the slave 202 are detected by a force detector to feedback a deviation between the forces to the master side, hereby controlling the force of the master side by a force control section 204 and controlling the force of the slave side by a force control part 204′.
There is further proposed a control device of robots equipped with such a force detector and a force control part as described above, capable of realizing stable force control with high accuracy even for hard material objects and of possessing a flexible property even when any part of an arm is contacted with the object, as disclosed in reference 2.    Reference 1: Laid-Open Patent Publication No. 2002-307336    Reference 2: Laid-Open Patent Publication No. 2001-198870